Electrostatic voltmeter

An Electrostatic Voltmeter is an instrument that measures voltage without charge transfer.

It can accurately measure surface potential (voltage) on materials without making physical contact and so there is no electrostatic charge transfer or loading of the voltage source.

Explanation

Many voltage measurements cannot be made using conventional contacting voltmeters because they require charge transfer to the voltmeter, thus causing loading and modification of the source voltage. For example, when measuring voltage distribution on a dielectric surface, any measurement technique that requires charge transfer, no matter how small, will modify or destroy the actual data.

Principle of operation

In practice, an electrostatic charge monitoring probe is placed close (1 mm to 5 mm) to the surface to be measured and the probe body is driven to the same potential as the measured unknown by an electronic circuit. This achieves a high accuracy measurement that is virtually insensitive to variations in probe-to-surface distances. The technique also prevents arc-over between the probe and measured surface when measuring high voltages.

External links

* [http://www.thebakken.org/artifacts/es-balance.htm The Bakken Library and Museum - Electrostatic Voltmeter]